I have to propose a structure for a compound. I am given the chemical formula, I
ID: 878729 • Letter: I
Question
I have to propose a structure for a compound. I am given the chemical formula, IR spectrum, and HNMR spectrum. I don't want to post all of that here because I do want to do the actual problem by myself.
In the HNMR spectrum there is a quartet of peaks around 6.8ppm that integrates to just 1 hydrogen. What functional group or structure could this quartet represent. I'm not asking for the whole structure or anything, I just want to know what information does this quartet alone provide us.
I'll put more information in a comment if it is necessary to answer the question. Thanks!
Explanation / Answer
Solution :-
6.8 ppm value is very close to the aromatic proton shift value
therfore it is possible that the aromatic ring proton is coupling with the two other protins and giving peaks as doublet of doublet which appears are quartet.
because H with any other electron negative group do not generally show such a downfield value
Therefore the it is the ring proton which is having electron donating groups therefore its ppm value is less than 7 pp m and appears as quartet therefore it may be double of doublet peaks.